In the ensuing scuffle, police used capsicum spray, batons and Tasers.

"The scene was frightening, violent and chaotic," Mr MacMahon said.

"I have no doubt it would have been terrifying for many, if not all, of those involved."

At that point, Mr Bosevski, who had earlier taken methamphetamine, punched one of the officers in the face.

He was then struck at least nine times with a baton, handcuffed twice and placed facedown on the ground by police officers, one of whom placed a knee on his back.

When he was turned over, three minutes and 44 seconds later, he was unconscious and he died a short time later.

Mr MacMahon found positional asphyxia did not play a role in his death.

"I cannot therefore be satisfied that the officers placing their knee on Steven's back was a contributing factor to his death," he said.

Instead, he found Mr Bosevski died from cardiac arrest as a result of several factors including his medical background, morbid obesity, drug-taking and "a period of intense physical exertion that occurred while being restrained".

Mr MacMahon noted when police arrived at the scene, they did not discuss the appropriate action to take.

Instead, the officers said they approached Tony Bosevski "with a view to investigating (his) involvement in a potential offence".

"If that was the case, then it was not an appropriate basis for police action and, as it turned out, amounted to little less than flapping a red rag at a bull," Mr MacMahon said.

"The intervention of the officers appear to have ignited the situation even if the officers were not acting in a hostile fashion.

"The failure to give consideration as to how to handle a potentially volatile situation amongst a group of males fuelled by alcohol in a confined space, as well as the potential dangers to patrons and the officers themselves, was in fact a gross error of judgment.

"... With more consideration by the officers, the whole incident might well have been avoided."

He recommended training should be provided to officers involved in crowd control situations.

Mr Bosevski's sister, who was in court for the finding, put her hand to her mouth as it was handed down.